Wheelchairs typically include a frame, three or four wheels rotatably mounted to the frame, and a seat in which the user sits. The wheelchair can be propelled by one or more of several methods. For example, the wheelchair frame can include handles projecting rearwardly behind the seat. The handles are accessible to an operator who can push or pull the wheelchair from behind. One drawback with this arrangement is that the user is dependent upon the operator for propulsion and may not be able to easily move about when the operator is not present.
One approach to addressing this problem is to provide the wheelchair with an on-board propulsion device, such as an electric motor. However, the motor can significantly increase the cost and weight of the wheelchair. Another approach is to provide the rear wheels of the wheelchair with inwardly or outwardly extending rims that users can engage with their hands to roll the wheelchair along. This approach may not be efficient because it relies on the user's hands and arms, which may not be as strong as the user's legs or may be otherwise engaged. Accordingly, many users who still have some use of their legs propel themselves by kicking the ground in front of them to push the wheelchair backwards. This approach also suffers from several drawbacks. For example, the wheelchair users face opposite their direction of travel and cannot easily see where they are going. Some users may attempt to address this drawback by digging their heels into the ground ahead of them and pulling themselves and the wheelchair forward. However, this method is difficult to perform and is not very efficient due to the structure of the leg.